| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a vehicular power supply device capable of lowering a voltage of a main-battery prior to switching from off to on of a relay when a voltage of a sub-battery is lowered than the voltage of the main battery with a low-cost constitution.SOLUTION: A main relay 17 is interposed between a main-battery 11 and a sub-battery 12. When the switching from off to on of the main relay 17 is required, a voltage of the main-battery 11 and a voltage of the sub-battery 12 are investigated. When the voltage of the sub-battery 12 is lower than the voltage of the main-battery 11, the main relay 17 is subjected to electric conduction to ISG3 before the main-relay 17 is turned on from off and, thereby, the voltage of the main battery 11 is lowered.</p> |
